Dungeon Wisp has three entrances: far West, slightly west, and east of the Honesty shrine in Ilshenar. The first levels are populated by Wisps and Ogres, but as you advance down the dungeon levels you start to see Poison Wisps and Wisp Lords, Cyclops and Titans. Deeper yet, you may be unlucky enough to encounter some true horrors, such as a Devourer of Souls. Coming across this foe, or one of many others, as paragon could lead to a quick death.
You can reference this map, but the spawns are not accurate.